<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
    <style>
        /*【1】text-decoration：应用范围是所有元素，没有继承性。多个设置是替换，不是累加*/
        .und{
            text-decoration: underline;
        }
        .over{
            text-decoration: overline;
        }
        .lth{
            text-decoration: line-through;
        }
        .bl{
            text-decoration: blink;
        }
        .father{
            color: black;
            text-decoration: underline;
        }
        strong{
            color: red;
            text-decoration: none;
            /*【2】子元素即便设置了下划线无，仍然有，因为机制是父元素有下划线，父元素的*/
            /*下划线经过了子元素而已。但是个别浏览器版本能消除。*/
        }
        strong{
            text-decoration: underline;
            /*【2-1】但我们有另外一种让子元素的下划线区别出来的能力，就是再次设置下划线，*/
            /*这样就会让子元素拥有和父元素不一致的下划线，从而区别出来。*/
        }
    </style>
</head>
<body>
<div>
    <p class="und">this place will action underline</p>
    <p class="over">this place will action overline</p>
    <p class="lth">this place will action line-through</p>
    <p class="bl">this place will action blink</p>
</div>
<div>
    <p class="father">this place will action father and son
        <strong>sky action</strong>
        this place will action father and son
    </p>
</div>
</body>
</html>